Aspects Of Graphene Transfer For Graphene-based Devices

Since graphene was first isolated in 2004,related research on graphene has developed rapidly,and researchers have applied graphene to various devices to obtain better performance.Among many technologies related to graphene research,transfer technology is a major bottleneck that limits the industrialization of graphene applications.During the transfer process,graphene will be exposed to a variety of pollutants,which will inevitably cause damage and pollution to graphene films.Among the mainstream transfer methods studied so far,acetone is used as an organic solvent to remove polymeric pollutants.However,acetone has not been studied as a contact material before its impact on graphene films.This article mainly studies transfer The effect of the process on graphene-based devices,especially the possible pollution of graphene surfaces caused by acetone immersion.It was found that the C=O bond in acetone would break to form polyether polymers and attach to the surface of graphene.Performance has an important impact.This article first reviews the structure,growth methods,physical properties,and application prospects of graphene,and then mainly introduces the common transfer methods of graphene prepared by CVD methods,mainly the intermediate transfer methods(PMMA,TRT,PDMS),direct Dry and wet transfer methods and large-scale transfer methods(roll-to-roll,hot-press),analyze the pollutants contacted during the transfer process,and the impact of pollutants on the properties of graphene,and propose a widely used acetone reagent Whether there is any influence in the graphene transfer process is the key argument of this thesis.The graphene samples required for this experiment were prepared based on the CVD method,and high-quality graphene with negligible defect density was obtained.The Raman spectrum of the acetone molecule was studied,the effect of acetone on graphene was confirmed,and the experiment was designed It was confirmed that the C=O bond in acetone would react on the surface of graphene.Next,the reaction process of the C=O bond was analyzed,and it was inferred that the product molecule was large,and the interaction between graphene and the product molecule was mainly Van der Waals force.It was proved by STM measurement and DFT simulation that the C=O bond was broken.And form chain and cyclic polyether polymers.Finally,a simple device structure was designed,and the effect of polymerized pollutants on the photoelectric properties of graphene thin films was studied.It was verified that the effect of polymerized pollutants on graphene thin film devices was mainly caused by photoelectric conversion,which excluded the effect of photothermal conversion.Further improvements in the transfer method provide ideas.